Re: [syzbot] INFO: trying to register non-static key in __timer_delete_sync

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    75da437a2f17 Merge branch '40GbE' of git://git.kernel.org/..
git tree:       net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=179ffde0c80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6e5fc864153bbc8c
dashboard link: https://syzkaller.appspot.com/bug?extid=1e164be619b690a43d79
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12d2dfb7480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13a81a07480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1ee7fdbb5171/disk-75da437a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/74233a046cf5/vmlinux-75da437a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a59b1d7b14b0/bzImage-75da437a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1e164be619b690a43d79@xxxxxxxxxxxxxxxxxxxxxxxxx

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 5075 Comm: syz-executor387 Not tainted 6.2.0-rc7-syzkaller-01590-g75da437a2f17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 assign_lock_key kernel/locking/lockdep.c:981 [inline]
 register_lock_class+0xf1b/0x1120 kernel/locking/lockdep.c:1294
 __lock_acquire+0x109/0x56d0 kernel/locking/lockdep.c:4934
 lock_acquire kernel/locking/lockdep.c:5668 [inline]
 lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
 __timer_delete_sync+0x5d/0x1c0 kernel/time/timer.c:1555
 del_timer_sync include/linux/timer.h:200 [inline]
 sfq_destroy+0x82/0x140 net/sched/sch_sfq.c:725
 qdisc_create+0xaca/0x1150 net/sched/sch_api.c:1329
 tc_modify_qdisc+0x488/0x19c0 net/sched/sch_api.c:1679
 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6174
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1942
 sock_sendmsg_nosec net/socket.c:722 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:745
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2501
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2555
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2584
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fcf276b9e69
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdba938b58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf276b9e69
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007fcf2767e010 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 00007fcf2767e0a0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
------------[ cut here ]------------
ODEBUG: assert_init not available (active state 0) object: ffff88802ba73540 object type: timer_list hint: 0x0
WARNING: CPU: 0 PID: 5075 at lib/debugobjects.c:509 debug_print_object+0x194/0x2c0 lib/debugobjects.c:509
Modules linked in:
CPU: 0 PID: 5075 Comm: syz-executor387 Not tainted 6.2.0-rc7-syzkaller-01590-g75da437a2f17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
RIP: 0010:debug_print_object+0x194/0x2c0 lib/debugobjects.c:509
Code: df 48 89 fe 48 c1 ee 03 80 3c 16 00 0f 85 c7 00 00 00 48 8b 14 dd a0 d1 a6 8a 50 4c 89 ee 48 c7 c7 60 c5 a6 8a e8 56 68 b4 05 <0f> 0b 58 83 05 ee 4c 64 0a 01 48 83 c4 20 5b 5d 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003b5f210 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000000000
RDX: ffff888020570000 RSI: ffffffff8166195c RDI: fffff5200076be34
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 203a47554245444f R12: ffffffff8a4ea980
R13: ffffffff8aa6cc00 R14: ffffc90003b5f2c8 R15: ffffffff816f9ff0
FS:  00005555573c4300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004585c0 CR3: 00000000299a3000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 debug_object_assert_init lib/debugobjects.c:899 [inline]
 debug_object_assert_init+0x1f8/0x2e0 lib/debugobjects.c:870
 debug_timer_assert_init kernel/time/timer.c:792 [inline]
 debug_assert_init kernel/time/timer.c:837 [inline]
 __try_to_del_timer_sync+0x72/0x160 kernel/time/timer.c:1412
 __timer_delete_sync+0x144/0x1c0 kernel/time/timer.c:1573
 del_timer_sync include/linux/timer.h:200 [inline]
 sfq_destroy+0x82/0x140 net/sched/sch_sfq.c:725
 qdisc_create+0xaca/0x1150 net/sched/sch_api.c:1329
 tc_modify_qdisc+0x488/0x19c0 net/sched/sch_api.c:1679
 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6174
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1942
 sock_sendmsg_nosec net/socket.c:722 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:745
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2501
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2555
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2584
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fcf276b9e69
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdba938b58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf276b9e69
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007fcf2767e010 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 00007fcf2767e0a0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>